> > When I nmap the CentOS box, I can’t see that port open. I’ve turned > off SELinux, so I’m not sure why I can’t see the open port 5432. > > What am I missing? It has to be something I’ve overlooked. > In postgresql.conf change the listen_address to be listen_address = '*' by default it only listens on localhost. It's documented in the file and is easily googleable. Use 'netstat -nlt' (or whatever the modern equivalent is) to see what's listening on which address. P.